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TVR Tasmin will not go over 4250 rpm?

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tr7andtvr

tr7andtvr

Jedi Hopeful
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New parts (distributor cap, rotor, plugs, wires, fuel pumps checked) It was doing this before the new parts. I have only had the car a month, and it has been doing this since I got it. The car gets just over 4000 rpm and does not go any farther. The only non-stock part that I know of on the car is a 17" flex fan.
 
Timing! I suspect your advance is sticking or there is another timing issue. I am no TVR expert, but you should check the timing curve with an advanceable timing light and a tuning tach so you can tell what advance you are getting at what RPM. Hopefully you have a manual or can get the timing specs from someone who knows.

Good Luck
Steve
 
Does it run start missing at that RPM or seem to run out of air/fuel? If missing it could be a Ignition Module which is a Ford item, if it starts acting like it is running out of fuel, then I would suspect Fuel Injection, which is a royal pain on this car. The CIS system is finicky, took me and a Porsche Shop better part of 3 visits to sort mine out.
 
I am not sure it is ever missing; it just does not go any higher. It’s like a rev limiter with out the shaking, and bouncing.
 
My guess is Fule Pressure, but I cannot figure out the CIS system so talk to a Bosch expert would be my best advice
 
Sounds like the catalytic converter is plugged.
A stuffed up converter mimics the symptoms of fuel starvation.
 
Just checked the TVR Bible and your problem sounds like a faulty throttle position sensor. It will give an incorrect reading to the ECU and cause the engine to gag or start to cut out.
Good Luck
Rick
 
The cat sounded like a good idea, took it off and it had been hollowed out by previous owner.

For a car with so much good engineering that exhaust system is crazy.
 
I had a similar problem with a truck once. Turned out the fuel filter was partially plugged. It would flow enough for low consumption rates, but wouldn't flow enough for high rpm pulling. Worth changing on a new to you car in any event.
 
My Alfa has the same problem... I've been slowly installing new components to try to find the culprit... New fuel pump, new lift pump, new pressure regulator. If those don't work, then next is coil, and flywheel sensors.
 
Replaced fuel filter "no luck". Does the car have a EGR valve? If so where is it located, and what does it look like?
 
How many miles on your car? You cannot just replace parts and hope for a fix. You need someone who has knowledge with the K-Jetronic system to diagnose. Special tools are required and also special knowledge. I would take it to a specialist someone who works on Porsche, Audi and VW. The Injection system really sucks and is quite finicky. Without the proper tools it is nearly impossible to adjust correctly.
 
I've read the L-Jetronic Manual (a couple actually)... and it IS pretty much a replace until problem disappears thing with L-jetronic. (K-Jetronic may be different) With certain items listed as culprits, in order of importance in the system needing checked out and replaced first. Vacuum hoses are the first main culprit... then sensors (the most expensive to replace). I've chosen to do a replacement schedule in lieu of actual diagnostics... just because I know my car needs the parts I'm replacing, because it's 22-23 years old, and so are the components in it... When it starts running good again, I won't be needing to replace another part in a few weeks.
 
this is (tr7andtvr)

The car has 35,000 miles.

I was looking for the cheap and easy fix, so I did not have to take it anywhere. I always try to do everything myself. This car is still very new to me, I know tr7's like the back of my hand.
 
The difference between the two is that K-Jetronic is basically Mechanical Injection and L Jetronic is Electronic Injection. They are quite different. Unfortunately for me, I cannot understand how to diagnose either one.
 
Ahhh... I didn't know the difference in the two... Just that L comes after K. L-jet was used on a lot of other cars though... VW's and BMW's... and a ton of japanese cars use a copy of the bosch system.
 
k jetronic was used on many cars-Ford,VW/AUDI,mercedes etc and does not rely on electronics-basically a mechanical injection and quite simple.Does the engine respond well up to 4000 revs?or does it struggle? Does it stay at those revs or does it falter and loose power?does it start well from cold?does it start well when hot?maybe be able to help you
 
My Alfa (L-jet) bogs down under load (barely able to carry the car up a hill at 2-3 mph. Idles smooth n nice, but won't rev much over 3000-4000 rpm even without a load. I first suspected fuel delivery problems, but when I disconnected the fuel pump, it sprayed fuel everywhere (nice high pressure), but I haven't replaced the pressure regulator yet. Then my dad suggested I might have a clogged cat.
 
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